Three geographically defined populations (totaling 85,000 persons) in predominatly black, poverty areas of Nashville are at risk of receiving three differing kinds of health care. In AREA 1, traditional health care predominates. In AREA 2, comprehensive health care with extensive outreach services is available in addition to traditional care. In AREA 3, comprehensive health care with limited outreach services is available in addition to traditional care. Health program characteristics are being monitored over a period of years in the three areas. The 1970 census and local mapping were used to create a sampling frame of addresses in each area. Data gathered during 1972-3 from household interviews obtained from a sample of households, followed by health examinations of a sample of individuals, have shown no significant differences across the three areas in professionally judged unmet needs for medical, dental and nursing services. It is hypothesized that health examinations of an entirely new sample of individuals during 1975-76 will show that unmet needs have been reduced most in Area 2, intermediately in AREA 3, and least in AREA 1. From birth and perinatal death records for 1969-71 it was shown that there were no significant differences across the three areas in birth and perinatal death rates. It is hypothesized that in comparing the years 1973-6 with 1969-72, perinatal death rates and other selected pregnancy indicators will show the most improvement in AREA 2, intermediate improvement in AREA 3, and least improvement in AREA 1. These studies provide a most unusual opportunity to measure the impact of programs over a period of years, using what are regarded as highly relevant outcome indicators. They also provide innovations in methodology as well as a possibly definitive storehouse of information about the unmet needs for health care, along multiple parameters, of a defined, predominantly low income, black population.